This invention relates to a flexible guide apparatus for supporting elongated flexible line elements in a generally U-shaped configuration connected between a pair of units which are mounted for moving relatively to each other in generally parallel relationship, and particularly for supporting power transmitting lines connected between a supply unit and a moving load unit.
Various movable industrial equipment may be connected by flexible elongated elements to other equipment. Typical installations are discussed in U.S. Pat. No. 3,330,105 wherein supply lines for transmission of energy and fluids such as electrical energy, pressurized gas and/or liquid and the like connect a supply or source to a consuming load device. In the installation, the load device moves back and forth over the source. The interconnecting flexible elements move in a U-shaped path as the result of the movement of the load device relative to the source. The flexible elements should be supported and preferably protected from the surrounding environment, as generally set forth in the above patent. Various chain-type guide devices have been suggested in the prior art and some are commercially available. Typical systems are shown in U.S. Pat. Nos. 4,111,236; 4,084,370; 3,921,388; 3,848,047; 3,772,875; 3,664,619; 3,546,875; 3,382,668; 3,337,696; 3,330,105; 3,282,044; 3,291,921; 3,197,954; 3,157,376; 3,089,349; 2,975,807; and 2,864,907. These and similar patents generally disclose flexible element guides consisting of a series of articulated chain link elements pivotally interconnected to each other and arranged with spaced straight beam sections connected by a curved transfer or re-entry section to establish the desired orientation and movement of the flexible elements. The chain link units are specially constructed to permit the necessary pivotal movement of the individual links for movement about the curved re-entry section of the unit while preventing opposite pivotal movement to create upper and lower supporting beam sections for the energy transmitting lines to the opposite sides of the re-entry section. The chain link units are specially constructed and arranged to hold and locate the flexible elements within the re-entry section on a neutral bending axis to essentially avoid stretching and compression of the element as it moves about the re-entry section. A theoretical discussion of the relationship is given in U.S. Pat. No. 2,864,907. The controlled bending of the cable or other flexible line is important to prevent the creation of fatigue and damage to the element as it moves back and forth through the bend or re-entry section, and thereby contributes to a long operating life for the element.
Such guide devices have generally been made as chain link elements with supporting crossbraces having individual guide openings for physically supporting the several flexible elements. Enclosures have also been suggested to protect the cables from the surrounding environment. A sheet metal enclosure is shown in U.S. Pat. No. 3,330,105. A similar total enclosure formed of a series of tubular sheet-metal elements with reverse bent and mating edges is also shown in U.S. Pat. No. 4,111,236.
A sheet metal construction is not particularly adapted to application in those environments where abrasion must be avoided. The energy carrying devices are often electrical cables, hydraulic or pneumatic cables, conduits or the like. It is of course extremely important that the cable supporting guide construction minimize any interengaging abrasive engagement with the flexible elements. Many of the proposed units with the special channel supports and the like must also be carefully constructed to avoid the sharp abrasive edges or the like. Although various prior art guides are commercially available, and others have been shown in patents, certain disadvantages exist in such devices from the standpoint of construction and functioning.
There is therefore a need for a tubular enclosure having means to reliably support the flexible elements with the appropriate beam and bending characteristic while providing for practical commercial production.